| Library of Congress|
The LC Linked Data Service is an initiative of the Library of Congress that publishes authority data as linked data. It is commonly referred to by its URI: id.loc.gov.
The first offering of the LC Linked Data Service was the Library of Congress Subject Headings (LCSH) dataset, which was released in April 2009.
Library of Congress Subject Headings (LCSH)
Library of Congress Name authorities
Library of Congress Classification—because LC Classification uses a different MARC format than LC Authorities, mapping LC Classification to MADS/RDF was more difficult than mapping LCSH or LC Name authorities.
Library of Congress Thesaurus for Graphic Materials
Various MARC codes
Various preservation vocabularies
Library of Congress Linked Data Service Wikipedia
The service presents data in MADS/RDF and SKOS where appropriate, but also uses its own ontology to describe classification resources and relationships more accurately. All records are available individually via content negotiation as XHTML/RDFa, RDF/XML, N-Triples, and JSON.
Each vocabulary is also available to download in its entirety. Id.loc.gov does not currently provide a SPARQL endpoint.
All of LCSH are cross linked with RAMEAU (Répertoire d’autorité matière encyclopédique et alphabétique unifié), an authority file from the Bibliothèque nationale de France.
The id.loc.gov site uses a fairly lightweight Python program to serve linked data.